The invention relates to a holding device and more particularly to a holding device which fits around the edge of paving blocks.
Paving blocks are commonly used in landscaping to achieve both a decorative and a utilitarian function.
However, the natural freezing and thawing cycle of the ground upon which blocks are laid, as well as vehicular and pedestrian traffic, causes movement of the blocks. Such movement destroys both the decorative and the utilitarian function of the blocks.
Thus, it becomes well settled in the art that it is highly desirable to hold paving blocks in place. Various edge support arrangements exist to hold paving blocks in place. The edge support arrangements of the prior art are difficult to construct and bring to bear on the problem.
Typical of the problems caused for an edge support arrangement is the fact that various surfaces are presented by the edge of paving blocks where the holding mechanism is desired. In some cases the edge of the paving blocks can present a straight line to be supported. In other cases, the edge of the paving blocks can present an arcuate (or curved) surface for an edge support arrangement to support. By arcuate is meant a curved or irregularly shaped surface.
When this paving surface is arcuate, it is difficult to adjust the holding mechanism to the appropriate shape. When it is straight it is possible to hold the paving block in position with a straight support mechanism. However, two completely separate mechanisms are required by the prior art for holding the paving blocks in position, when different edges are presented. It highly desirable to hold the paving blocks in position with one type of device, which can be easily modified at the job site. If this can be accomplished, it is easier to provide the necessary edge supporting material.
Also, the length of the edge support arrangement required can provide a problem. The longer the edges of the paving blocks which require support, the more difficult it is to achieve the desired positioning of the edge support arrangement. Furthermore, as the paving block area extends, the edge may be arcuate, then straight, and then back to arcuate again in a continuous fashion. It is highly desirable to have one easily modified unit to provide the required edge support for any edge shape of the paving blocks.
Long units of an edge support arrangement present many difficulties. Firstly only certain lengths of material are permitted to be hauled on highways. Secondly, handling of long units presents difficulties at the job site. Additionally, other transportation problems can exist. For example, the structure cannot be compactly fitted into a truck or transportation means. So the long units provide transportation problems and handling difficulties on the job site.
To provide for joining of units of an edge support arrangement to achieve a desired length to solve the long unit problems presents many other problems. The joint inherently produces a weakness in the device. Functioning of the joining device on the job site also presents a problem. Many different parts are required for the joining. A special effort is required to have all of those parts available. Joint strength is inversely proportional to the ease of joining the units. Having the required Joining members available may also present a problem.
Holding the edge support in position is a difficult matter. The strength of the support must be maintained, and the support must be left in position--even during a freeze/thaw cycle. The freeze thaw cycle can force nails holding the support to come loose. A single unit is desired to achieve that holding force. Structure must be developed to avoid that problem.
Nothing holds a paving block holding device in position better than a good root system. It is important that the root system be able to lock into the holding device. Holding devices known in the prior do not permit this desired root interlocking.
Thus, it can be seen that there are a substantial number of problems in achieving an appropriate support for a group of paving blocks.